Fire damage to block

[docs]

My engine block was on the machine being line bored when the machine shop burned down. The fire in that area was hot enough to melt the aluminum arms holding the boring jig. My question is: After the block was subjected to that temperature and then cooled down by the water from the fire department is that block still usable? I am concerned that due to stresses introduced into it it may now be much more subceptible to cracks developing now or later. What are your opinions?

[Terry, NJ]

I want to say that your block has been normalized or stress relieved, but what bothers me is the cool water hitting it. especially from one side. I'd have it magnafluxed and if it's still ok, then go ahead and use it.
Terry

Originally Posted by docs

My engine block was on the machine being line bored when the machine shop burned down. The fire in that area was hot enough to melt the aluminum arms holding the boring jig. My question is: After the block was subjected to that temperature and then cooled down by the water from the fire department is that block still usable? I am concerned that due to stresses introduced into it it may now be much more subceptible to cracks developing now or later. What are your opinions?

[Tom Wesenberg]

I'd do the same as Terry suggests.

I've heard so many horror stories about fires the past few years that now I unplug many things that I never used to, and I also cut all power to my outbuildings when I'm not in them.

[H. L. Chauvin]

Also agree with Terry's magnafluxed test.

The water bit on a hot block could be questionable; but most probably the fire did not hurt anything for this reason:

Have a 1920's welding manual showing how to properly weld vintage cast iron engine blocks without causing multiple cast iron stress cracks as follows:

1. Place block on ground & line perimeter around block with bricks about 18" high.

2. Remove block & build a roaring fire with "lots" of wood stacked up within the brick wall perimeter, & keep adding wood until the enclosure is full of burning embers.

3. With a shovel, make a recess in the embers & set block on embers, & cover block with burning embers, & cover embers with galvanized roofing.

4. When hot, remove block, weld block with acetylene torch, & place block back covered with embers & covered with metal roofing.

5. Allow block to cool until embers burn out.

Naturally, this was the same 1920's generation that baked bread at home & killed & plucked their own chickens.

No doubt the bread was good, the corn fed chickens were better than chickens today -- my guess from stories that I heard from vintage welders is that the weld also lasted -- in 2013, if one makes bread once, allows time for dough to rise, & then bake -- with this much time consuming work, the next loaf will most probably come from the store -- at least the block was not discarded.

[docs]

Tnx guys for the reassuring comments. Especially the last one from h l Chauvin. Still not comfortable withit but at least I have food for thought before investing a lot of money in a rebuild.

[Ed Northrop]

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In a fire aluminum melts and disappears seem like

[Bob C]

Are the engine and chassis matching numbers? If not and you would fell better why
not get another block and sell the burnt one. What does the guy that owned the machine
shop say.

Bob

[docs]

Yes it is a matching number. The shop owner said he thought it would still be ok but I didn't know so that is why I asked the question.

[Tom Wesenberg]

Did the babbit melt?

Did the rear aluminum seal melt?

I think if you magnefux it and check the deck for flat, if they both show OK, then you should be fine.

[H. L. Chauvin]

Hi docs,

In reply no. 5., in your mentioning "food for thought", can't figure if you wanted the homemade bread or the live chickens. Both were good!

[Kurt in NJ]

Try the cam --see if the cam bearing bores are in line

Check the cylinder bores --are they still round

Is the block deck flat, the pan rails --main parting area

Take a small fine file, see if there are any head spots on corners of the casting --if the file just skates the sudden cooling made hard spots.

Of course look for cracks, and a pressure test too to find hard to see cracks or other waterjacket damage (there have been some posts of freshly rebuilt engines that have leaks out the ports)

Try a valve guide in it's bore

[docs]

The block had been magnafluxed (ok) and babbit had been poured. Block had been cleaned and no aluminum seal was in it. Haven't. found the camshaft over there yet. Lots of good ideas here though.

[Domino]

If its not good enough to use, selling it to someone else is questionable unless one does so with full disclosure. Jus my opinion.